An engine cylinder may receive fuel via a port fuel injector and a direct fuel injector. The port fuel injector may supply fuel to a cylinder during times when an intake valve of the cylinder receiving the fuel is open or closed. If the intake fuel is closed when the port fuel injector is activated, the port injected fuel will be inducted to the cylinder during a next open intake valve interval. Direct fuel injectors may supply fuel to a cylinder during an intake stroke or a compression stroke for a combustion event in the compression stroke. By port injecting fuel and directly injecting fuel to a cylinder during a cylinder cycle, the port injected fuel can increase an amount of fuel provided to the cylinder so that the cylinder may operate at higher loads while the direct fuel injector provides charge cooling to reduce the possibility of engine knock. However, if a port fuel injector becomes degraded, the engine cylinder with the degraded port injector may not operate in a same way as engine cylinders where port and direct injector are operating as is desired.
The inventors herein have recognized the above-mentioned disadvantages and have developed an engine fueling method, comprising: receiving inputs to a controller; and deactivating all port fuel injectors of an engine in response to reduced performance of a sole port fuel injector based on the inputs to the controller.
By deactivating all port fuel injectors of an engine in response to degradation or reduced performance of a single sole port fuel injector, it may be possible to provide the technical result of operating an engine with cylinders that preform substantially the same even in the presence of port fuel injector degradation. In particular, deactivating all port fuel injectors of an engine provides similar operating conditions for all engine cylinders so that no one cylinder may perform differently than other cylinders. Consequently, all active engine cylinders may provide similar levels of torque output and emissions. Further, because the engine cylinders are restricted to a single type of injector, all engine cylinders may be controlled via a simplified strategy that does not require some cylinders to be controlled one way and other cylinders to be controlled a different way.
The present description may provide several advantages. For example, the approach simplifies engine control strategy during period of degradation. In addition, the approach may provide for more uniform cylinder operating and output. Further, the approach provides a repeatable procedure for mitigating the effects of port fuel injector degradation.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.